| 主权项 |
1. A light emitting diode (LED) driving circuit having an efficiency improvement function, the LED driving circuit being connected to an alternating current (AC) power supply, the LED driving circuit comprising:
a rectifier circuit connected to the AC power supply to generate a rectified voltage; a control circuit connected to an output of the rectifier circuit; an LED load and a constant-current circuit connected to an output of the control circuit in series, the LED load and the constant-current circuit being connected in series with each other; a capacitor connected in parallel to the LED load and the constant-current circuit, the capacitor being configured to smooth the output of the rectifier circuit; and a detection circuit configured to detect whether the rectified voltage exceeds a predetermined voltage value, the predetermined voltage value being equal to or greater than a sum of a voltage applied to the LED load when the LED load is turned on and a voltage applied to the constant-current circuit at a time when the LED load starts being turned on, wherein the control circuit is configured to control the output of the rectifier circuit to be passed when the rectified voltage does not exceed the predetermined voltage value, and configured in such a way that a first operation of blocking the output of the rectifier circuit and a second operation of passing the output of the rectifier circuit are repeatedly performed when the rectified voltage exceeds the predetermined voltage value. |
